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High

Sensitive Information Exposure in Gravity SMTP for WordPress REST API

IdentifiersCVE-2026-4020CWE-200· Exposure of Sensitive Information…

The Gravity SMTP plugin for WordPress is vulnerable to sensitive information exposure in all versions up to and including 2.1.4. The issue is caused by a REST API endpoint at /wp-json/gravitysmtp/v1/tests/mock-data being registered with a permission_callback that unconditionally returns true, allowing unauthenticated access. When the query parameter ?page=gravitysmtp-settings is appended, the plugin's register_connector_data() method populates internal connector data and the endpoint returns roughly 365 KB of JSON containing the full System Report. Exposed information includes the PHP version, loaded extensions, web server version, document root path, database server type and version, WordPress version, active plugins and their versions, active theme, WordPress configuration details, database table names, and any API keys or tokens configured in the plugin.

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ANALYST BRIEF

Impact, mitigation & remediation

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Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows unauthenticated attackers to obtain extensive reconnaissance and configuration data about the target WordPress environment. The exposed system report can disclose sensitive operational details and secrets, including plugin-configured API keys or tokens, which may enable follow-on attacks against the WordPress instance, connected services, or adjacent infrastructure. Even where direct credential compromise is limited, the disclosure materially lowers the cost of targeted exploitation by revealing exact software versions, enabled components, filesystem paths, and database characteristics.

Mitigation

If you can’t patch tonight, do this now.

Until a patched version is deployed, restrict or block access to the vulnerable REST route /wp-json/gravitysmtp/v1/tests/mock-data at the web server, WAF, or reverse proxy layer, especially for unauthenticated users. Disable the plugin if it is not operationally required. Limit public exposure of the WordPress instance where feasible, monitor for requests to the affected endpoint including those with the page=gravitysmtp-settings parameter, and rotate any secrets stored in the plugin because they may already have been disclosed.

Remediation

Patch, then assume compromise.

Update the Gravity SMTP plugin to a version newer than 2.1.4 if a vendor fix is available. The vulnerable REST endpoint should be protected by a proper permission_callback that enforces authentication and authorization before returning diagnostic or connector data. The endpoint should also avoid returning full system-report content to untrusted callers, and any secrets such as API keys or tokens should be excluded or redacted from responses. If exposure may have occurred, rotate any API keys or tokens configured in the plugin and review logs for unauthenticated access to /wp-json/gravitysmtp/v1/tests/mock-data.
PUBLIC EXPLOITS

Exploits

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VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

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